lib: add comments to exposed but internal symbols

[babeltrace.git] / src / lib / logging.h

diff --git a/src/lib/logging.h b/src/lib/logging.h
index 498be21ede8c87fc00801745a1919d5242e97cf6..f4890ce34f0a07c3211b1e0445e14e7d743c8e8a 100644 (file)
--- a/src/lib/logging.h
+++ b/src/lib/logging.h
@@ -34,6 +34,8 @@
 
 #include "logging/log.h"
 
+#define BT_LIB_LOG_LIBBABELTRACE2_NAME "libbabeltrace2"
+
 extern
 int bt_lib_log_level;
 
@@ -49,21 +51,63 @@ int bt_lib_log_level;
 /* See `CONTRIBUTING.adoc` for usage */
 #define BT_LIB_LOGF(_fmt, ...) BT_LIB_LOG(BT_LOG_FATAL, _fmt, ##__VA_ARGS__)
 #define BT_LIB_LOGE(_fmt, ...) BT_LIB_LOG(BT_LOG_ERROR, _fmt, ##__VA_ARGS__)
-#define BT_LIB_LOGW(_fmt, ...) BT_LIB_LOG(BT_LOG_WARN, _fmt, ##__VA_ARGS__)
+#define BT_LIB_LOGW(_fmt, ...) BT_LIB_LOG(BT_LOG_WARNING, _fmt, ##__VA_ARGS__)
 #define BT_LIB_LOGI(_fmt, ...) BT_LIB_LOG(BT_LOG_INFO, _fmt, ##__VA_ARGS__)
 #define BT_LIB_LOGD(_fmt, ...) BT_LIB_LOG(BT_LOG_DEBUG, _fmt, ##__VA_ARGS__)
-#define BT_LIB_LOGV(_fmt, ...) BT_LIB_LOG(BT_LOG_VERBOSE, _fmt, ##__VA_ARGS__)
+#define BT_LIB_LOGT(_fmt, ...) BT_LIB_LOG(BT_LOG_TRACE, _fmt, ##__VA_ARGS__)
 
 /*
  * Log statement, specialized for the Babeltrace library.
  *
- * Use one of the BT_LIB_LOGF*() macros above instead of calling this
+ * This function does NOT check that logging is enabled for level `lvl`:
+ * you must check it manually with BT_LOG_ON().
+ *
+ * Use one of the BT_LIB_LOG*() macros above instead of calling this
  * function directly.
+ *
+ * This function would normally be BT_HIDDEN, but it is used by the Python
+ * plugin provider, which is conceptually part of libbabeltrace2, but
+ * implemented as a separate shared object, for modularity.  It is therefore
+ * exposed, but not part of the public ABI.
  */
-
 void bt_lib_log(const char *func, const char *file, unsigned line,
                int lvl, const char *tag, const char *fmt, ...);
 
+#define BT_LIB_LOG_AND_APPEND(_lvl, _fmt, ...)                         \
+       do {                                                            \
+               bt_lib_maybe_log_and_append_cause(                      \
+                       _BT_LOG_SRCLOC_FUNCTION, __FILE__,              \
+                       __LINE__, _lvl, _BT_LOG_TAG,                    \
+                       (_fmt), ##__VA_ARGS__);                         \
+       } while (0)
+
+/* See `CONTRIBUTING.adoc` for usage */
+#define BT_LIB_LOGE_APPEND_CAUSE(_fmt, ...)                            \
+       BT_LIB_LOG_AND_APPEND(BT_LOG_ERROR, _fmt, ##__VA_ARGS__)
+#define BT_LIB_LOGW_APPEND_CAUSE(_fmt, ...)                            \
+       BT_LIB_LOG_AND_APPEND(BT_LOG_WARNING, _fmt, ##__VA_ARGS__)
+
+/*
+ * Like bt_lib_log(), but also appends a cause to the current thread's
+ * error object.
+ *
+ * Note that, unlike bt_lib_log(), this function does check that logging
+ * is enabled for level `lvl` before logging. This is to ensure that,
+ * even though logging is disabled, the function still appends an error
+ * cause, as the error reporting system does not rely on logging.
+ *
+ * Use one of the BT_LIB_LOG*_APPEND_CAUSE() macros above instead of
+ * calling this function directly.
+ *
+ * This function would normally be BT_HIDDEN, but it is used by the Python
+ * plugin provider, which is conceptually part of libbabeltrace2, but
+ * implemented as a separate shared object, for modularity.  It is therefore
+ * exposed, but not part of the ABI.
+ */
+void bt_lib_maybe_log_and_append_cause(const char *func, const char *file,
+               unsigned line, int lvl, const char *tag,
+               const char *fmt, ...);
+
 #define BT_LIB_LOG_SUPPORTED
 
 #endif /* BABELTRACE_LIB_LOGGING_INTERNAL_H */